A tool mount with a solid-body joint is already known from the machine manual “Precitech Nanoform® 200/Nanoform® 300” of Precitech Inc., Keene, N.H., USA, pages 14-15. In order to adjust the turning tool blade to the center of rotation, the tool mount has a fine adjustment that is arranged opposite the tool in relation to the axis of rotation of the solid-body joint.
A spindle drive is known from DE 20 2010 007 456 U1, which thanks to the use of piezo-elements assures a fine adjustment motion superimposed on the spindle motion. The piezo-elements result in a displacement of the one-sided bearing of the spindle contrary to a clamping force of disk springs or solid-body joints, for example, and thus ensure a movement of the spindle in its longitudinal direction corresponding to the deformation of the piezo-element. On the other hand, the use of the mentioned solid-body joint as a joint for the swiveling of the work piece or tool is not described.
This is a typical example of the use of a solid-body joint. What is characteristic is the adaptation of the solid-body joint to the tool mount. Since the tool mount with the tool has a relatively small mass, the force to be absorbed by the fine adjustment is predominantly attributable to the deformation of the solid-body joint. The weight of the tool mount with the tool is negligible.
Machine tools, especially nonround lathes for the fabrication of plastic lenses or spectacle glasses, have become increasingly dynamic in the past, so that in the meantime highly dynamic machining processes with oscillation frequency of around 100 Hz are common at the leading manufacturers.
Alternatively to the use of a solid-body joint for the height adjustment of the tool there is known the use of a tilted linear axis for the tool. Thanks to the tilting, not only a feed motion but also a motion component in the direction perpendicular to this is possible, so that the height of the tool can be adjusted. But this comes with the drawback that changes in the tool position attributable to a heat-related expansion of the tool drive unit will affect two position values, so that a continual calibration goes along with temperature change.